People with at least four of the five newly discovered gene variations had a 50 percent increased risk of dying from prostate cancer than people who had just two or fewer of the variations, according to the research, published in the journal Cancer Epidemiology, Biomarkers & Prevention.

The discovery could lead to a blood test for men who test positive for prostate cancer, but aren't sure whether to undergo treatment for the cancer or just watch and wait to see if it becomes worse.

"The panel of markers we’ve identified provides the first validated evidence that inherited genetic variants play a role in prostate cancer progression and mortality," study researcher Janet L. Stanford, co-director of the Program in Prostate Cancer Research at the Fred Hutchinson Cancer Center, said in a statement.

Prostate cancer tests, while life-saving, can be murky for both doctors and patients. Even if a patient's levels of prostate specific antigen (PSA) are high during a screening test -- a sign of prostate cancer -- it doesn't mean a surefire diagnosis for the disease. The patient must undergo further testing including a biopsy to determine if he actually has prostate cancer.

And once that is determined, it's hard to tell if the cancer is slow-growing and non-lethal, or if it's clinically significant, aggressive and needs immediate treatment. A man could undergo treatment for prostate cancer that is unnecessary, which would then bring about unnecessary costs and side effects.

The findings of this week could make that process clearer, and give doctors the information they need to determine if the prostate cancer tumor is slow-growing and non-lethal, or aggressive and deadly, HealthDay reported.

For the study, researchers analyzed blood samples from more than 1,300 people with prostate cancer (who were diagnosed between ages 35 and 74) who live in the Seattle area. Then, they added the DNA analyses from those samples with those from 2,900 Swedish men with prostate cancer.

By doing so, researchers were able to single out five single-letter mutations -- also called SNPs, which are a type of gene variation -- that seemed to strongly affect whether prostate cancer dangerously progresses -- to affect inflammation, tumor growth, development of blood vessels and cells death, HealthDay reported.